There was an unverified rumour floating around yesterday that up to 500,000 user accounts linked to the Call of Duty franchise of games had been hacked, with personal data potentially stolen. The information came from a now-deleted Twitter account who made the claims.
Activision has now officially gone on record to state that the information was "not accurate" and that the claims appeared to be a hoax. Many influencers helped to quickly spread the rumour after it had strated, with players encouraging each other to change their passwords.
Activison Support tweeted a message that refuted the claim there had been a hack, and that the company "investigates all privacy concerns." They did, however, remind players to make sure they take good care of their credentials, use two-factor where possible, and that they would recieve an e-mail if there had been any changes to their account.
This does not completely rule out the possibility there was some kind of hack or data leak, however, as the company didn't specifically state there hadn't been an attack of some kind. There's no evidence of an actual hack having taken place at this stage, however we'll be sure to keep an eye on the situation and report with any further developments.